从金属学角度来看，热轧与冷轧的界限应该以金属再结晶的温度来区分，即低于再结晶温度的轧制为冷轧；高于再结晶温度的轧制为热轧。而钢的再结晶温度一般在450℃～600℃范围之内。
From the point of view of metallization, the boundary between hot rolling and cold rolling should be distinguished from the temperature of recrystallization of metal, that is, the rolling that is lower than the recrystallization temperature is cold rolling, and the rolling that is higher than the recrystallization temperature is hot rolling. The recrystallization temperature of steel is generally within the range of 450 ~ 600.
棒材穿水冷却装置的基本原理是什么？
在精轧机后设有一个由数个水冷箱组成的可调水冷段，对棒材进行急剧冷却，使棒材表面形成马氏体***，在随后的温度***过程中，芯部热量散出对表面马氏体***可产生回火作用，结果棒材表面层为回火马氏体，芯部为细粒珠光体及索氏体***。这种***结构使棒材屈服极限和韧性提高，并具有良好的可焊性。Theyneedtobeheatedto1100and1250Cforrolling。
What is the basic principle of the bar water cooling device?
After the finishing mill, there is an adjustable water cooling section of several water cooling boxes. The rod material is cooled sharply to form martensite structure. During the subsequent temperature recovery process, the heat of the core can produce tempering on the surface martensite, and the surface layer of the rod is tempered martensite, the core is fine pearlite and Soxhlet body. This structure improves the yield limit and toughness of bars, and has good solderability.
所谓低温热轧是指稍高于再结晶温度下的轧制。提高轧制温度可以降低轧件温度的屈服应力，使变形功降低。但是由于变形功可以转化为热量，因此，当轧件温度的热损失主要是热辐射时，热损失量与轧件温度的4 次方成正比。
The so-called low temperature hot rolling is a rolling that is slightly higher than the recrystallization temperature. Increasing rolling temperature can reduce yield stress of workpiece and reduce deformation work. However, the deformation work can be converted into heat, so when the heat loss of the rolling temperature is mainly heat radiation, the amount of heat loss is proportional to the 4 time of the rolling temperature.
轧辊的弹性压扁沿辊身长度散布是不匀称的，若边部延伸率大。轧机支持辊的外貌肖氏硬度1样平常为HS45左右，在另1侧设专人观察，也会出现相反的环境，薄钢板通常以卷板和剪切成肯定长度和宽度的单张板投放市场。
The elastic flattening of the roll is uneven along the length of the roller body, and the elongation at the side is large. The appearance of the rolling mill support roll is about 1 HS45, which is normally observed on the other 1 sides, and the environment will occur. Thin plates are usually put on the market with rolled plates and a single sheet that is cut to a certain length and width.